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					ERGONOMICS
ERGONOMICS AS A CONCEPT

The term ergonomics was coined from the Greek words ergon (meaning "work")
and nomos (meaning "rules).So the literal meaning is "the rules of work,"
Ergonomics is the science of fitting the work-place conditions and job demands to
the capabilities of the working population. The goal of ergonomics is to make the
work place more comfortable and to improve both health and productivity. To meet
these goals, the capabilities and limitations of workers and their tools, equipment
and furniture are considered in conjunction with how they relate to particular tasks.
Most people have heard of ergonomics and think it is something to do with seating
or with the design of car controls and instruments. It is...but it is much more!
Ergonomics is the application of scientific information concerning humans to the
design of objects, systems and environment for human use. Ergonomics comes into
everything which involves people. Work systems, sports and leisure, health and
safety should all embody ergonomics principles if well designed.

DEFINITION


According to International Labour Organization, ergonomics is the application of the
human biological sciences in conjunction with engineering sciences to the worker
and his working environment, so as to obtain maximum satisfaction for the worker
and at the same time enhance productivity.
HISTORY


Later in the 19th century, Frank and Lillian Gilbert expanded Taylor's methods of
“SCIENTIFIC MANAGEMENT” in the early 1900s to develop "Time and Motion
Studies". They aimed to improve efficiency by eliminating unnecessary steps and
actions. By applying this approach, the Gilbert’s reduced the number of motions in
bricklaying from 18 to 4.5, allowing bricklayers to increase their productivity from
120 to 350 bricks per hour.
In the decades since the war, ergonomics has continued to flourish and diversify.
The Space Age created new human factors issues such as weightlessness and
extreme G-forces. How far could environments in space be tolerated, and what
effects would they have on the mind and body? The dawn of the Information Age has
resulted in the new ergonomics field of human-computer interaction (HCI).
Likewise, the growing demand for and competition among consumer goods and
electronics has resulted in more companies including human factors in product
design.

ORIGIN OF ERGONOMICS

Ergonomics is a relatively new branch of science which celebrated its 50th
anniversary in 1999, but relies on research carried out in many other older,
established scientific areas, such as engineering, physiology and psychology.


It originated in World War 2, when scientists designed advanced new and
potentially improved systems without fully considering the people who would be
using them. It gradually became clear that systems and products would have to be
designed to take account of many human and environmental factors if they are to be
used safely and effectively. This awareness of people’s requirements resulted in the
discipline of ergonomics.
USING ERGONOMICS

How do we use ergonomics? Ergonomics incorporates elements from many subjects
including anatomy, physiology, psychology and design. Agronomists apply their
diverse knowledge to ensure that products and environments are comfortable, safe
and efficient for people to use.
Ergonomics can be used in every possible sphere of our lives. But we have tried to
focus on some of the important aspects, where ergonomics should not be ignored.


For that purpose we have divided the usability of ergonomics into the following
sections:


    Ergonomics and the Computer User

Why is it Important?

The personal computer is rapidly becoming a common household item and is now a
necessary tool for all small businesses. There is a growing segment of the population
that uses the computer exclusively for its vocation and it is in this group that we
have begun to see the physical effects of spending long hours day after day at the
computer. With improvements in technology the computer users are positioned to
perform more and more functions without leaving their workstation.

Here are some of the ergonomic ways to ensure that the using of the computer
doesn’t prove fatal to your health.

Machine Set-up


    Visibility:-     You must be able to see what you are doing easily to avoid eye
    strain and neck pain. Have adequate amounts of light. Florescent lights are not
    very good, natural (sun) light is best. Reduce glare as much as possible, not only on
    your screen but also on the rest of your work areas including the keyboard. Hoods,
drapes, glare screens and changing the lights can do wonders. Rearrange things
until you can see well and it feels comfortable for you.

Chairs:-        As with visibility factors, experiment with chair height and/or tilt.
Try different chairs. Keep trying until you get it the way your body likes.

Keyboards:-        Be sure to get the height right to prevent too much bend at the
wrist and allow the forearm to have some support. The arms should hang loose to
prevent the shoulder muscles from cramping. Many keyboards can tilt;
unfortunately, most of them tilt the wrong way.

Mouse:- The continual clicking and small, precise motions involved in mouse use
are a repetitive action that can be a health hazard. A few basic rules can help make
handling this convenient input devise safer and more comfortable:
1.) Hold the mouse loosely. "White knuckling" the mouse creates too much
tension. Use a light touch when you click.
2.) Use you whole arm and shoulder to move the mouse, not just your wrist. Don't
rest your forearm on the desk while you move the mouse.
4.) Keep your wrist relaxed and neutral, not bent. The click button should be about
the same height as your keyboard.


Desks:     Make enough space so that you have room to work, especially if your
pushing your mouse around. Use a paper holder to keep letters or books semi-
vertical and at eye level. Your work space should be set up so that you need not
twist your neck.
    HUMAN SET-UP


    Posture:-        No one posture is perfect. You do not have to be "military" but
    getting comfortable is essential. The most important rule is to avoid prolonged
    positions. Shake your hands and shoulders now and then. Keep lose.

    Eyes:-      After good lighting and avoiding glare, the most important eye
    consideration is to look away from the screen occasionally. It really helps. Also,
    don't forget to blink. Blinking moistens the eyes to prevent burning from dryness.

    Warm up:-      Just as an athlete prepares for the game by stretching and loosening
    the joints and muscles to prevent injury and enhance performance, you too should
    prepare for a marathon session surfing the Net. Prevention is better than repair.



    Ergonomics and driving

Why is it important?

As our reliance on the automobile increases due to long distance job commutes
driving has become a significant part of our daily routine. By spending more and
more time in cars our driving can now be considered a major source of physical and
psychological stress in day-to-day living.

Stressors of Driving

The challenge of the manufacturer is to strike a balance between safety and comfort.
With the prime ergonomic elements being posture, force and repetition it is posture
that is most important to the driver. Any deficiencies in postural design of the car
seat contribute to tension and fatigue on the part of the driver and subsequently
detract from performance. There are portable support systems/commuter supports
designed to be added to the existing car seating. These compensate for ineffective
car seat design.
Neck and Shoulder Pain

With long distance driving aches and pains in the legs, low back, mid, upper back
and neck are experienced. With our hands on the steering wheel and the forward
posture of the shoulders there is added stress on the shoulders and upper back.

To prevent rounding of the shoulders the driver must have easy access to the
steering wheel without having to fully extend the arms and at the same time
comfortably reach the foot pedals without having to stretch the legs. Compact
vehicles are notorious for poorly accommodating tall individuals. If the ceiling is too
low for an erect seated position the driver is forced to crunch down in the seat with
a forward head posture. Short drivers must be able to slide the seat forward to the
extent that they do not have to lean forward and place the head in a forward
position.

Low Back Pain

Several studies have shown a relationship between driving and low back pain. Risks
of both low back and neck pain tend to increase as daily driving time increases

For people with a history of low back problems it is recommended that they choose
a vehicle with a higher curb height so they are not traumatized when getting in and
out of the car. The driver should enter the car first by sitting down and then
swinging the legs under the wheel. Features that are included in most modern
vehicles include automatic transmissions and power steering. These features lessen
any twisting of the spine and strain to the low back.
   Ergonomics at home

Why is it important?

The opportunity we have in our home that we do not always have in our work area
is the ability to create a user-friendly environment. As each room in the house
serves a specific function we need to come up with ideas on how we can set up the
room to best suit our needs so there is more efficiency and less stress in the
activities of the house.

The Living Room

The next room we enter is the living room. This is the room in which we usually do
most of our relaxing in the form of reading, socializing or watching TV. These
activities require ergonomically designed couches, recliners and chairs. Watching
television is best done from an easy chair or recliner. Directional light should be
used while reading that will only illuminate a specific target area.

The Kitchen

The kitchen is where we store, cook and prepare food. It is most practical to use a
refrigerator that has a freezer on the bottom with the most commonly used foods on
the top or shelf that has the easiest access. Most people have refrigerators that are
set up in such a way that they are forced to bend over at the waist to access the
much frequently used foods. The most commonly used utensils should be within
easy reach. Special kitchen tool designs make chores easier as in opening jars.
Professional cooks like professional wood workers know the importance of using
only sharp knives. When used skillfully, it is more dangerous to use a dull knife than
a sharp one. Using a utensil that is not suited for the task (improvising) is a sure
invitation to an accident.
The bathroom

This is where most accidents in the house occur, usually from slipping. Bath and
floor mats that provide good traction are essential for the purpose of preventing
slips and falls. Hand bars are also crucial to prevent falls. Common flaws in
bathroom design are low bathroom sinks and showerheads. These will tend
precipitate low back and neck injuries respectively. All faucets in the house should
be fitted with a user-friendly variety in which low force is necessary to turn the
water on and off. Turning knobs that are poorly designed can put unnatural stress
on the wrists thereby causing injury to wrist tendons.

   Ergonomics and kids

Why is it important?

If we provide for their ergonomic needs we can increase children’s involvement in
their environment and thereby cultivate mastery, productivity and independence.

A Place for Toys

Children work at play and toys are their tools. They should have their toys and
things stored in such a way that they are readily accessible. If their toys are
organized in open shelves or in transparent bins children are visually reminded of
what they have and as a result will stay involved and interact more with their
physical surroundings The area of play is close to the ground and it should be safe
from hazards and easy to clean. Since young children spend most of their time close
to the ground they should have their own throw rug to protect the knees and
provide a cushion from falls.
Kids and Backpacks

Research is significant in view of the fact that school children are being burdened
with heavier backpacks than ever before. Health care professionals are reporting
increases in visits by children for various musculoskeletal complaints such as neck,
back and shoulder pain, fatigue, muscle pain and numbness. Bags that are carried in
one hand also put an uneven burden on the body. The pack should rest against the
body naturally and the straps should be padded and as wide as possible.

Furniture for Children

Chairs and tables must be proportionate to their size and the feet should be firmly
planted on the ground or at least on a footrest. It is most practical to have furniture
that can grow with the child. These include tables that have adjustable legs and
chairs that have adjustable seats and footrest height.

Ergonomics and the office

Why is it important?

By incorporating ergonomic principles into the functional design of a contemporary
office, the workers become more productive and efficient. Each worker's tasks
center around a workstation and the configuration of the workstation depends on
the performance duties of each worker.

Workstation

The goal for each worker should be to maximize productivity and efficiency with
minimal stress and injury. In a modern day office the centre of the worker's activity
revolves around a computer, desk and chair. The application of ergonomics is most
important to the activities that make up the bulk of the workers time.

To prevent the worker from wasting energy by moving in and out of a chair, space
must be used efficiently. The working area can be divided into zones. Zone 1 is the
area containing materials most frequently accessed and therefore within a 12-inch
reach. Those materials less frequently used are in zone 2 or within a 20-inch reach.
Those materials that are seldom used are in Zone 3 or greater than 20 inches away
from the worker. The idea is to use shelving and cubicles that are compactly
designed to organized things into respective zones. Sometimes it is necessary to
organize shelving into portable units such as carts with casters. For ease of
operation these casters should have low rolling resistance and a centralized locking
system. Unnecessary motions interrupt a smooth workflow and expend wasted
energy. They also cause cumulative trauma to the back, neck and shoulders.
Stretches and exercises can be performed at the workstation without disrupting the
work routine.

By taking a proactive role in initiating ergonomic programs the business bottom line
is enhanced through worker productivity and decreased healthcare costs.

Ergonomics and factory/assembly work

Factory and assembly line type work is a carryover from the industrial revolution
and has evolved over the years as a result of our increasing knowledge of
ergonomics. The requirements of the work are extremely varied and the resulting
consequences on human health can range from repetitive or cumulative trauma
disorders to death. For this reason it is essential for companies to establish
ergonomic programs for ensuring the safety, efficiency, and productivity of various
jobs.

It is a natural goal of these companies to minimize job related health costs and
personnel turnover and to maximize productivity by workers. To this end it is
important for companies to develop an overall ergonomic strategy as an integral
part of their business strategy. Specifically these companies must come to
understand how human performance issues contribute to production bottlenecks,
problems in quality control, injury and turnover rates and how they can find
solutions through production layout and tool design.
Work Surfaces

A worker is certain to get neck, upper back and shoulder pain if neck flexion exceeds
20 degrees for prolonged periods of time. The optimal viewing range is between
horizontal and 45 degrees. Work surfaces should be round and padded where
elbows, forearms and wrists can be rested. Certain work stations aids include
ladders, stools and carts with casters ergonomically designed with low rolling
resistance which have shock absorbing and noise free characteristics. They should
have central locking systems and be equipped with proper push/pull assists.

Ergonomics and Automotive Mechanics

Why is it Important?

The work of auto mechanics is particularly awkward and demanding and frequently
results in abuse to the wrists, elbows, and spine in general. The worker’s body is
forced to conform to the various engine configurations and auto design.
Automobiles have evolved over the last few years toward smaller and more compact
machines and as a result the mechanics tools have had to undergo a refinement in
ergonomic design to function in very confined space.

Working under the Hood

In applying ergonomics to work we normally think of “fitting the task to the human”
but unfortunately in mechanic work we tend to “fit the human to the task.” The
result is cumulative trauma from long hours of awkward static postures. The
mechanic is forced to lean forward while working under the hood of the vehicle and
this leads to low back strain.

One way to work on engine parts under the hood that are particularly difficult to
reach is by utilizing a special overhead creeper which consists of a padded chest
board that is supported on top of a ladder-like apparatus.
The Mechanic Workstation

The mechanic’s job is facilitated by setting up the workstation in a way that tools
can be accessed quickly and without an unnecessary expenditure of energy. To
minimize the low back strain that results from manual lifting and carrying heavy
engine parts and tools, sturdy utility carts with casters should be used as a means of
transport. The casters should have low rolling resistance with shock dampening and
noise free characteristics. Tool carts with trays should be organized into a system
which arranges the most frequently used tools within easy reach. The tools should
be easily modified and portable depending on the nature of the job at hand.

FACTORS OF CONSIDERATION

To produce a workplace that will minimum amount of strain to the worker,
ergonomics takes into account the following three factors


      Anthropometric data
   Anthropometry is the study of measurement of physical features of human
   beings. It studies the strength of various muscles and ranges of body movement.
   The data on human body dimensions are of two types
   -   Structural dimensions
   These are body dimensions of a person in a static condition. There are two static
   positions, namely sitting and standing.
   -   Functional dimensions
   These are the body dimensions of a person in motion. This is more important
   than the structural dimensions as most of the working conditions are dynamic in
   nature.


      Human activity analysis
   Movements
   Human strength and endurance
   Speed and accuracy
      Motion economy


What Is Motion Economy?


Motion economy helps achieve productivity and reduce Cumulative Trauma at the
workstation or sub-micro level. The Principles of Motion Economy eliminate wasted
motion, ease operator tasks, reduce fatigue and minimize cumulative trauma such as
Carpal Tunnel and tendonitis.

PRINCIPLES OF MOTION ECONOMY


Summarized from Ralph M. Barnes

1.0 Use of Human Body                                Provide     for     adequate     visual

      The two hands should begin end                 perception. Good illumination is

       their motions at the same time.                the first requirement.

      The two hands should not be idle              Arrange      the     height     of    the

       at the same time except during                 workplace and chair for alternate

       rest periods.                                  sitting     and     standing,        when
                                                      possible.
      Motions of the arms should be
       made        in     opposite       and         Provide a chair of the type and

       symmetrical        directions     and          height to permit good posture.

       should be made simultaneously           3.0 Design of Tools and Equipment
      Hand motions should be confined               Relieve hands of work that can be
       to the lowest classification with              done more advantageously by a
       which it is possible to perform                jig, fixture, or a foot-operated
       the work satisfactorily                        device.
      Momentum should be employed                   Combine            tools      whenever
       to assist the worker whenever                  possible.
       possible,    and    it   should    be
       reduced to a minimum if it must             Pre-position           tools        and
       be overcome by muscular effort.              materials.
      Smooth continuous motions of                Where      each   finger       performs
       the hands are preferable to                  some specific movement, such as
       zigzag motions or straight-line              in typewriting, the load should be
       motions involving sudden and                 distributed in accordance with
       sharp changes in direction.                  the inherent capacities of the
      Ballistic movements are faster,              fingers.
       easier, and more accurate than              Handles (i.e. cranks and large
       restricted        (fixation)     or          screwdrivers) should permit as
       "controlled" movements.                      much of the surface of the hand
      Rhythm       assists   smooth   and          to come in contact with the
       automatic performance. Arrange               handle as possible, especially
       the work to permit an easy and               when       considerable     force    is
       natural rhythm.                              necessary.
                                                   For     light         assembly,       a
2.0 Arrangement of The Work Place
                                                    screwdriver handle should be
      There should be a definite and
                                                    smaller at the bottom.
       fixed place for all tools and
                                                   Levers, crossbars, and hand
       materials.
                                                    wheels should be located in such
      Tools, materials, and controls
                                                    positions that the operator can
       should be located close in and
                                                    manipulate them with the least
       directly in front of the operator.
                                                    change in body position and with
      Gravity feed bins and containers
                                                    the        greatest        mechanical
       should       be   used    whenever
                                                    advantage.
       possible.
                                             4.0 Body Segment Classes
      Drop delivers should be used
       whenever possible.                          Use motions with the lowest
                                                    feasible class.
      Materials and tools should be
       located   to   permit     the   best
       sequence of motions.




DISORDERS CAUSED.

MUSCULOSKELETAL DISORDERS: Musculoskeletal Disorders (MSD) can range
from general aches and pains to more serious Problems. Medical practitioners do
recommend that all the users who use computers regularly should report signs and
symptoms as early as possible to prevent serious injury or permanent damage.

Musculoskeletal Disorders: Types

    The different types of Musculoskeletal Disorders are as follows:

      Repetitive Stain Injury
      Carpal Tunnel Syndrome
      CARPAL TUNNEL SYNDROME:

Carpal Tunnel Syndrome is a pinched nerve (called the Median nerve) in the wrist.
Carpal Tunnel Syndrome (CTS) is the inflammatory disorder that is caused due to
repetitive stress, physical injury or any other condition that causes the tissues
around the median nerve to inflate. carpal tunnel is a small canal or tunnel runs
from the forearm through the wrist. Bones form three walls of the tunnel, which are
bridged by strong, broad ligament. The median nerve passes through this tunnel,
which actually supplies feeling to the thumb, index, and ring fingers, the nine
tendons that flex the fingers and also provides function for the thinner muscles,
which are actually the muscles at the base of the thumb.
When the protective lining of the tendons within the carpal tunnel inflamed and
swell or when the ligament that forms the roof becomes thicker and broader leads
to Carpal Tunnel Syndrome. This ultimately results in pain, numbness, and tingling
sensation in the wrist, hand, and fingers leaving the little finger, as it not affected by
the median nerve which is nothing but the Carpal Tunnel Syndrome.




The key risk factors in the workplace that causes the Carpal Tunnel Syndrome.

      Repetition
      High force
      Awkward joint posture
      Direct pressure
      Vibration, and
      Prolonged constrained posture.

REPETITIVE STRAIN INJURY :

Repetitive Strain Injury (RSI) is the general word that is used to describe the
prolonged pain experienced in shoulders or hands or neck or arms. Repetitive Strain
Injury occurs when the movable parts of the limbs are injured. Repetitive Strain
Injury usually caused due to repetitive tasks, incorrect posture, stress and bad
ergonomics. Repetitive Strain Injury generally causes numbness, tingling, weakness,
stiffing, and swelling and even nerve damage. The chief complaint is the constant
pain in the upper limbs, neck, shoulder and back. The Repetitive Stress Injury
generally effects the group of workers who generally use excessive and repetitive
motion of the neck and head are at high risk.
USE ERGONOMICS TO AVOID MUSCULOSKELETAL DISORDERS.


                                                             - a few minutes at least
once an hour


alternately to avoid strain
                  t equipment such as footrests, wrist/palm rests, and document
holders if required
                                              – it is always recommended to hold the
mouse lightly and click gently.
   Establish healthcare management to emphasize the importance of early
    detection and treatment of musculoskeletal system disorders for preventing
    impairment and disability.
   Identify effective controls for tasks that pose a risk of musculoskeletal system
    injury and evaluate these approaches once they have been instituted to see if
    they have reduced or eliminated the problem.
   Gather data to identify jobs or work conditions that are most problematic, using
    sources such as injury and illness logs, medical records, and job analyses.

Case studies.

Dental Hygiene Work

Task

The job entails setting up a work station, which includes assembly of hand tools and
arrangement of lighting. The dentist also examines a patient, completes scaling and
root planning, polishing, and flossing.
Problem

Due to limited access to the oral cavity and the nature of the tasks, dental hygiene
work requires prolonged static trunk and neck flexion, and awkward shoulder and
wrist positions.

Intervention

Use chairs that are able to increase or decrease in height and move back to fit the
comfort of the operator. They are also designed to provide body support in the front
and the back. Surrounding work surfaces are low and positioned to make the reach
for tools smooth and on a horizontal plane at elbow height for a seated person.

Cost:

RS.31500/- approx.



Evaluation of Intervention

Pros :-

1. Chairs improve access to the patients oral cavity with less awkward positions
2. Supports trunk and forearms in forward position, and supports back in the
   backward positions
3. Less cervical spine flexion

Cons:-

The back of the chair may interfere with the headrest of the patient’s chair, or block
the vision of the operator

Criteria

Reduction of Identified Risk Factor
No New Risk Factors Introduced

Other Possible Interventions:

   Ergonomic hand instruments

CASE 2

Hairstyling

Task

Hairstyling at a hair saloon, which includes working with blow dryers, curlers, and
scissors.

Problem

The beauticians complain of back and wrist pain when using the curling iron. The
major risks involved are repetitive, forceful grasping, awkward wrist posture due to
ulnar deviation, and shoulder abduction.

Intervention

Redesign the curling iron so that there is not as much repeated wrist deviation.
Modifications to the curling iron include adaptable handles that can be used without
excessive bending or twisting of the wrist. A switch will be used to trigger the curler
to spin, causing the hair to wrap around the hot iron.




                    Cost: Rs. 11250/- approx.
Evaluation of Intervention

Pros:-

1. Reduces the need to deviate the wrist
2. Lowers peak force applied during task activity

Cons:-

1. May affect use and precision
2. Does not reduce shoulder abduction

Criteria

1. Reduction of Identified Risk Factor
2. No New Risk Factors Introduced

Other Possible Interventions:

1. Modify chairs to optimize working range
2. Lower mirror and counter height

CASE 3

Design of push carts

Task

To push and pull heavy loads with a cart

Problem

Risks associated with pushing and pulling of heavy loads


Intervention
On 4-wheeled carts, swivel casters should be located on the handle end, so that they
can be used on all 4 wheels. The casters themselves should be at least 4― in size.
The wheel can be replaced with hard plastic or pneumatic tires. The bearing should
be maintained regularly. Handle height should be in the range of 36―-42―. The
handles should accommodate a pushing movement, as opposed to a pulling
movement. Some equipment suggestions that accommodate these needs are the
electric hand truck, the electric push cart, and the electric platform truck.

Cost:

   1. Electric hand truck – Rs. 180000/- approx.
   2. Electric push cart – Rs. 81000/- approx.
   3. Electric platform truck – Rs. 67500/- approx.

Evaluation of Intervention


Pros:-
   1. Swivel casters on all 4 wheels will allow for maneuvering in very tight spaces
   2. Harder casters decrease necessary force


Cons:-

   1. Requires regular maintenance
   2. Wheels cannot be easily adjusted to changes in terrain
   3. Batteries require charging

Criteria

1. Reduction of Identified Risk Factor
2. No New Risk Factors Introduced
3. Productivity not Reduced
Other Possible Interventions:

   1. Tread and corrosion should be monitored

CASE 4

   Palletizing of Beer Cases

Task

Loading of pallets with cases of beer

Problem

The general body posture risk factors include trunk forward bending and twisting,
and shoulder extension. Other risks were the vertical distance of the lift at the
destination, increased load to the lumbar spine caused by horizontal distance, and
whole body exertions.

Intervention

A redesigned workstation will alleviate same problems. The most effective
intervention to improve vertical distance of the lift is the installation of a scissor lift
to increase the height of the first tier of cases to a more appropriate lifting zone.
Another way to reduce vertical distance reach is to restrict the pallet height to 4
tiers of beer cases. A rotating device under the pallet would reduce the horizontal
distance of the lift. Pallets should also be placed at the end of an extended conveyor
to increase buffer capacity for performing other job tasks.

Cost:

Rs. 202500/- approx.

Evaluation of Intervention

Pros:-
   1. Accommodates workers of various heights
   2. Minimal asymmetry in moving boxes
   3. Reduces carry distance
   4. Increasing buffer capacity increases safety

Cons:-

   1. Increases the number of pallet being filled per day, which shifts injury to low
         back

Criteria

1. Reduction of Identified Risk Factor
2. No New Risk Factors Introduced
3. Productivity not Reduced

Other Possible Interventions:

1. Design the conveyor to route the boxes to 2 buffer zones, divided by a barrier,
   for symmetry.
2. Install a lift aid to decrease load amount lifted by workers.

CASE 5

 Telephone Information Center Operator

Task

 To attend calls and provide information to all the customers.

Problem

1. Viewing the city map requires leaning over the desk; more extreme bending is
   required to see the northern portion of the city.
2. The downtown area located in the middle right section of the map is accessed
   most frequently and is the most detailed, increasing visual demand.
3. Light from windows and overhead lights is reflected on the glass plate covering
   maps and on computer monitors at many of the workstations, depending on
   orientation with respect to light sources.
4. Desks are too high at 31" for many of the employees, requiring awkward reaches
   for the keyboard.
5. The new chairs being ordered are too low for the height of the desks, requiring
   additional forward bending and standing to view the map.
6. Placement of monitors in desk corner requires neck twisting; several of the
   present monitor arms are not functioning properly

Intervention

Replace current desks with workstations with height- and slope-adjustable input
platforms offering forearm support. Incline the back half of the map to at least 60
degrees. The map will need to be either creased, curved, or re-printed onto 2 halves
and then covered with an anti-glare sheet. This brings the hard to see top part of the
map within viewing distance and allows the keyboard to remain flat on the work
surface. However, glare on the flat portion of the map will still be present. The
monitor should be positioned to one side of the map.

Cost:

Approx. Rs. 30000 per workstation

Evaluation of Intervention


Pros:-

1. Reduced forward bending to read map
2. Glare reduced
3. Keyboard at optimal level
4. Neck twisting reduced to view monitor

Cons:-

1. Glare still exist on bottom half of Map

Criteria

1. Reduction of Identified Risk Factor
2. No New Risk Factors Introduced
3. Productivity not Reduced

Other Possible Interventions:

1. Sit-stand workstation with the map hung on a wall
2. Digitize the map and have it available on the monitor screen
3. Enlarge frequently used areas of the map

CASE STUDY ON TOYOTA

Overview: Toyota, the fourth largest automaker in North America, has three vehicle
assembly plants in the United States and one in Canada. Toyota Logistics in
Georgetown, Kentucky was facing significant design changes between two model
years, resulting in potential ergonomic risk and inefficiencies, particularly with the
rear spoiler installation. Humantech assisted Toyota's Georgetown, Kentucky
logistics operation in improving the rear spoiler installation for one of its hottest
selling vehicles. A combination of low-cost and high-impact improvements resulted
in reduced ergonomic risk and a 62% improvement in cycle time, translating into a
$262,000 annual savings in direct labor costs. Long-term savings include decreased
medical and workers' compensation expenses, lower absenteeism, and reduced
training of new associates.

Toyota's Motor Manufacturing Assembly
Task Prior to Abatement (Description)
Workers had to perform auto plants normal production assembly. The tasks involve
various postures, reaching distances, pinching or gripping, and manual lifting.

Task Prior to Abatement (Method Which Identified Hazard)
There were an increasing number of work-related injuries and illnesses, most of
which related to upper extremities.

Ergonomic Risk Factor (Posture)
Workers had excessive forward bending to perform a task.
Workers had to climb inside a car to install a part.

Ergonomic Solution (Administrative Controls)
Record keeping was made easier.
Training programs were provided.
Job rotation program was set.
CTD detection and early prevention were incorporated in the ergonomics
intervention program.
Personal protective equipment, physical therapy, and workplace accommodations
were provided.
With indication of early symptoms of CTDs, workers are sent to industrial health
services for a medical evaluation.




Ergonomic Solution (Engineering Controls)
An automated chair for moving the seated worker in and out of the vehicle has been
developed.
The work surface has been tilted to minimize the worker's forward bending.


Ergonomic Solution (Benefits)
All workers that perform the tasks now have reduced exposure to CTDs.
Reduction in workers' compensation costs.
Ergonomic Solution (Method Which Verified Effectiveness)
CTD-related incidents have been reduced by implementing ergonomics
interventions.


Comments
This ergonomics evaluation system, although argued to be too subjective, pinpoints
problem areas before they become critical.

				
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